Run tests against MariaDB

[swissspidy]

See also #115

Would be useful for cases such as wp-cli/db-command#275 and wp-cli/db-command#280

Could be like 1 additional step in the matrix or so.

[swissspidy]

We can use the MariaDB 11.4 LTS version which is maintained until May 2029.

[wojsmol]

@swissspidy This requires only to add matrix entries - see https://github.com/shogo82148/actions-setup-mysql?tab=readme-ov-file#distribution We are using this action to setup database server in tests.

[swissspidy]

Thst‘s great, so it‘s a very simple addition :) Wanna submit a PR?

Maybe MariaDB 11.4 and PHP 8.3?